Low frequency electrostatic ultrasonic atomising nozzle

Abstract

The invention discloses a low-frequency electrostatic ultrasonic atomization nozzle that relates to an electrostatic atomizer in the field of agricultural engineering. The low-frequency electrostatic ultrasonic atomization nozzle comprises a transducer back cover, piezoelectric ceramics, a transducer front cover, an ultrasonic horn and a fastening screw. Furthermore, the fastening screw is set through the transducer back cover, the piezoelectric ceramics and the center round hole of the transducer front cover in sequence; a liquid inlet channel is designed in the axial center of the ultrasonic horn; an air intake channel is designed in a position that deviates from the axial center; the top of the ultrasonic horn is machined as a concave spherical surface; and a suspended ball is arranged on the concave spherical surface. Moreover, compressed air in the axial eccentric position is used for rotating the suspended ball at high speeds; a charging needle is electrified to generate an electric field for the suspended ball that the droplets generated by low-frequency ultrasonic atomization and can electrostatically atomize again, and it can make the droplets take on an electrostatic charge; finally, the electrified droplets are sprayed out from the nozzle. The low-frequency electrostatic ultrasonic atomization nozzle breaks through the bottleneck of a low-frequency ultrasonic atomization nozzle that struggles to generate ultrafine droplets and enables the droplets to take on static electricity to increase adhesion so that the droplets can attach to crops more efficiently.

The invention claimed is: 
     
       1. A low-frequency electrostatic ultrasonic atomization nozzle, comprising:
 a back cover; 
 an ultrasonic vibrator comprising a transducer back cover, piezoelectric ceramics, and a transducer front cover; 
 an ultrasonic horn, the length of which is determined as the half-length of an ultrasonic wave, the ultrasonic horn comprising a liquid inlet channel configured in an axial center thereof and an intake channel configured at a position that deviates from the axial center of the ultrasonic horn, wherein the intake channel is configured to inject compressed air and has a concave spherical surface configured for levitating balls; 
 a fastening screw, wherein the fastening screw is attached through center holes of the transducer back cover, the piezoelectric ceramics, and the transducer front cover in sequence; 
 a levitating ball with a V-shaped annular groove on its outer surface that is made of a metallic conductor; 
 a charging needle restrained by a spring and the V-shaped annular groove on the levitating ball that uninterruptedly charges the levitating ball; 
 an insulating sleeve configured to insulate the charging needle; 
 a bracket; and 
 a socket connecting the bracket and the insulating sleeve; and 
 a spring in the insulating sleeve and configured to ensure the charging needle uninterruptedly contacts the levitating ball, 
 wherein the bracket is connected with flanges of the ultrasonic horn by set screws, and 
 wherein the bracket fixes the socket. 
 
     
     
       2. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , wherein the depth of the annular groove on the outer surface of the levitating ball is 1-2 mm. 
     
     
       3. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , wherein the levitating ball and the charging needle are made of copper. 
     
     
       4. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , wherein the diameter of the insulating sleeve is 0.2-0.4 mm greater than the diameter of the spring and 0.05-0.1 mm less than the diameter of the socket, and wherein the spring is against the insulating sleeve to restrict reciprocating movement of the charging needle in the socket. 
     
     
       5. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , wherein two same-sized holes are respectively drilled in the bracket and the socket to enable a charged wire to pass through the socket and the bracket to directly charge the charging needle. 
     
     
       6. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , wherein the bracket is a rectangular frame, wherein the set screws comprise bolts and nuts, and wherein the ultrasonic horn is fitted with a gasket. 
     
     
       7. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , wherein the ultrasonic horn and the transducer back cover are made of insulating ceramic materials. 
     
     
       8. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , comprising a main part, wherein the main part comprises the transducer back cover, the piezoelectric ceramics, the transducer front cover, and the ultrasonic horn, and wherein a vibration frequency of the low-frequency electrostatic ultrasonic atomization nozzle is in a range of 20-100 kHz. 
     
     
       9. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , wherein the charging needle applies a static voltage of less than 500 V to the levitating ball. 
     
     
       10. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , wherein the diameter of the levitating ball is in a range of from 13 mm to 17 mm. 
     
     
       11. The low-frequency electrostatic ultrasonic atomization nozzle of  claim 1 , wherein the charging needle applies a static voltage of less than 2000 V to the levitating ball.